In conventional lithium secondary batteries, metallic lithium is used as the negative electrode. In this conventional battery, lithium deposited during charging of the battery is active and it tends to react on the electrolyte to form dendrite growth thereby resulting in penetrating a separator between the negative electrode and a positive electrode, further, causing an electrical short circuit, or the precipitated lithium is powdered and separated. Therefore in the conventional lithium battery a sufficient reversibility between charging and discharging cannot be expected.
To suppress the reaction on the electrolyte, and dendrite growth, and separation of the precipitated lithium, there is proposed a method of using a lithium alloy such as lithium-aluminum for the negative electrode of the lithium battery based on an increment of a diffusion factor of lithium in the negative electrode using the alloying reaction of lithium. This proposal is effective for improving the characteristics of the lithium secondary battery. However, a problem in the proposed method is that it is difficult to obtain a sufficient reversibility between charging and discharging of the battery under a high current since an over potential occurs during deposition of lithium under a high charging current.